1. Field of the Invention
The present invention relates to selected polymeric furanone magenta colorants and a process for making these colorants. Furthermore, the present invention relates to phase change inks containing these colorants as well as selected resins and waxes that incorporate these colorants therein.
2. Description of the Relevant Art
Phase change inks in digital printing applications (also sometimes called solid inks or hot melt inks) have in the past decade gained significant consumer acceptance as an alternative to more traditional printing systems such as offset printing, flexography printing, gravure printing, letterpress printing and the like. Phase change inks are especially desirable for the peripheral printing devices associated with computer technology, as well as being suitable for use in other printing technologies such as gravure printing applications as referenced in U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE4205713AL assigned to Siegwerk Farbenfabrik Keller, Dr. Rung and Co.
In general, phase change inks are in the solid phase at ambient temperature, but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the printing media, they quickly solidify to form a predetermined pattern of solidified ink drops.
They are easy to use and safe. They can be easily loaded into the printer by the user, generally in the form of solid sticks of yellow, magenta, cyan and black ink having a solid consistency similar to children""s crayons. Inside the printer, these inks are melted at an elevated temperature in a printhead having a number of orifices, through which the melted ink will be ejected onto the desired substrate such as media like paper or an overhead transparency film. Alternatively, the melted ink may be transferred to a rotating drum and then transferred to the substrate. As the ink cools on the substrate, it re-solidifies into the desired image. This resolidification process, or phase change, is instantaneous and a printed, dry image is thus made upon leaving the printer, which is available immediately to the user.
These phase change inks contain no solvents or diluent that can lead to undesired emissions. In all, the use and specific design of the phase change ink addresses many of the limitations of more traditional ink and printing processes.
Furthermore, because the ink is in cool, solid form at any time when the user can actually come in contact with the ink, and the ink is in a molten state only inside the printer (inaccessible to the user), it is generally safe to use. These inks also have long-term stability for shipping and long storage times.
The phase change inks generally comprise a phase change ink carrier composition, which is combined with at least one compatible phase change ink colorant. The carrier composition has been generally composed of resins, fatty acid amides and resin derived materials. Also, plasticizers, waxes, antioxidants and the like have been added to the carrier composition. Generally the resins used must be water-insoluble and the carrier composition may contain no ingredients that are volatile at the jetting temperatures employed. Also, these carrier ingredients should be chemically stable so as not to lose their chemical identity over time and/or under elevated temperature conditions.
Preferably, a colored phase change ink will be formed by combining the above described ink carrier composition with compatible colorant material, preferably subtractive primary colorants. The subtractive primary colored phase change inks comprise four component dyes, namely, cyan, magenta, yellow and black. U.S. Pat. Nos. 4,889,560 and 5,372,852 teach the preferred subtractive primary colorants employed. Typically these may comprise dyes from the classes of Color Index (C.I.) Solvent Dyes, C.I. Disperse Dyes, modified C.I. Acid and Direct Dyes, as well as a limited number of C.I. Basic Dyes. Also suitable as colorants are appropriate polymeric dyes, such as those described in U.S. Pat. No. 5,621,022 and available from Milliken and Company as Milliken Ink Yellow 869, Milliken Ink Blue 92, Milliken Ink Red 357, Milliken Ink Yellow 1800, Milliken Ink Black 8915-67, uncut Reactant Orange X-38, uncut Reactant Blue X-17, and uncut Reactant Violet X-80 or those described in U.S. Pat. No. 5,231,135.
Colored resin reaction products such as those described in U.S. Pat. No. 5,780,528 issued Jul. 14, 1998, and assigned to the assignee of the present invention, are also suitable colorants.
Polymeric colorants are increasingly being utilized in preparing commercial phase change ink jet inks, as well as potentially for use in other applications, such as gravure printing, and other types of inks and coating applications where coloration is desired. For example, the specific class of polymeric dyes characterized by: (1) an organic chromophore having (2) a polyoxyalkylene substituent and optionally (3) a carboxylic acid or non-reactive derivative thereof covalently bonded to the polyoxyalkylene substituent, as described in U.S. Pat. No. 5,621,022 (Jaeger et al.) possess several advantages; including:
(1) These polymeric dyes are very soluble in the phase change carrier composition and possess high water fastness and high resistance to xe2x80x9cbleedingxe2x80x9d or weeping of the color from the carrier composition when printed samples are subjected to high temperatures or humidity.
(2) These polymeric dyes are thermally stable in the carrier composition. This is important because the resulting phase change ink compositions may remain molten for weeks at a time in the ink jet printer, or otherwise at elevated temperatures.
(3) These polymeric dyes also act as a plasticizer for the formulation. This enables the formulator to replace at least a portion of the commercial plasticizer that is normally part of the formulations disclosed in the inks of U.S. Pat. Nos. 4,889,560 and 5,372,852.
(4) These polymeric dyes are compatible with each other and with most conventional powdered dyes currently used in phase change ink compositions. Thus, mixtures of inks of different colors do not form a precipitate when mixed together during the printing process. This compatibility also allows for the mixing of these polymeric dyes with powdered dyes of the same primary color into the same ink composition to achieve high color strengths that would not be possible with either dye type by itself.
While phase change ink compositions containing this class of polymeric dye colorants have had good commercial success, it must be noted that non-migrating, lightfast magenta colorants are absent from this class of polymeric dyes. The present invention provides a solution to the need for better non-migrating magenta colorants that possess the other advantages of this class of polymeric dyes.
The present invention is based on the discovery of a new class of oligomeric or polymeric furanone magenta dyes. The dyes are useful in a number of applications, including phase change inks. This new class of furanone magenta dyes can be made by a new and commercially viable synthesis that avoids the use of particularly hazardous starting materials and intermediates.
Therefore, one aspect of the present invention is directed to an oligomeric or polymeric furanone magenta colorant comprising a 3-cyano-4-phenyl-2(5H)-furanone adduct wherein the phenyl radical possesses an oligo or polyoxyalkylene substituent. This 3-cyano-4-(p-polyoxyalkylenephenyl)-2(5H)-furanone moiety, referred to above as the furanone adduct, can be further condensed with a variety of electron rich benzaldehyde moieties to produce magenta colorants.
Another aspect of the present invention is directed to a process for making a polymeric furanone magenta colorant comprising the steps of:
(1) subjecting an alkoxylated acetophenone to a halogenation reaction to form a halogenated alkoxylated acetophenone;
(2) subjecting the halogenated alkoxylated acetophenone to an organocarboxylate substitution reaction to form the organocarboxylate ester of the alkoxylated acetophenone;
(3) condensing the organocarboxylate diester of the alkoxylated acetophenone with an alkylcyanoacetate in the presence of base to form an alkoxylated furanone adduct; and
(4) condensing the alkoxylated furanone adduct with an electron rich aromatic aldehyde to form a polymeric furanone magenta colorant having at least one alkoxylated phenyl radical and derived from at least one aromatic aldehyde having a para-nitrogen and containing electron donating groups selected from the group consisting of alkyls, cycloalkyls, and polymers derived from alkyleneoxy or aryleneoxy moieties.
Still another aspect of the present invention is directed to a phase change ink composition comprising the combination of a phase change ink carrier and an oligomeric or polymeric furanone magenta colorant that comprises a furanone magenta chromophore having at least one alkoxylated phenyl radical and derived from at least one aromatic aldehyde having a para-nitrogen and containing electron donating groups selected from the group consisting of alkyls, cycloalkyls, and polymers derived from alkyleneoxy or aryleneoxy moieties.
And still another aspect of the present invention is directed to an isocyanate-derived colored resin composition comprising the reaction product of:
(a) an isocyanate or diisocyanate; and
(b) at least one nucleophile comprising an oligomeric or polymeric furanone magenta colorant having at least one alkoxylated phenyl radical and derived from at least one aromatic aldehyde having a para-nitrogen and containing electron donating groups selected from the group consisting of alkyls, cycloalkyls, and polymers derived from alkyleneoxy or aryleneoxy moieties.
And a further aspect of the present invention is directed to an isocyanate-derived colored wax composition comprising the reaction product of:
(a) an isocyanate or a diisocyanate; and
(b) at least one nucleophile comprising an oligomeric or polymeric furanone magenta colorant having at least one aromatic aldehyde having a para-nitrogen and containing electron donating groups selected from the group consisting of alkyls, cycloalkyls, and polymers derived from alkyleneoxy or aryleneoxy moieties.
It is a feature of the present invention that this class of furanone magenta dyes can be easily tailored to provide particular derivatives or species within this class that possess specific physical and chemical properties.
It is another feature of the present invention that the furanone magenta dyes of the present invention may be used as either the sole colorant material in a phase change ink or can be used with other conventional phase change ink colorant materials.
It is still another feature of the present invention that these polymeric furanone magenta dyes may be employed with conventional phase change carrier components (e.g., amide waxes, resinous components, tackifiers, toughening agents, hardeners, adhesion promoters and the like).
It is yet another feature of the present invention that this class of magenta dyes can be reacted with isocyanates and anhydrides and the like to form a tailored colored resinous material or waxy material that will be more compatible with other carrier components and, thus, less likely to settle or migrate in the molten or solid state, respectively.
It is an advantage of the present invention that this class of magenta dyes is easy to manufacture.
It is another advantage of the present invention that this class of magenta dyes is easy to handle and process as part of an ink system.
These and other aspects, features and advantages are obtained by the use of an oligomeric or polymeric furanone magenta colorant derived from a 3-cyano-4-phenyl-2(5H)-furanone adduct wherein the phenyl radical possesses an oligo or polyoxyalkylene substituent.
The preferred class of furanone magenta colorants comprise compounds of formula (I): 
wherein A is an oxyalkylene or aryleneoxy moiety; x is an integer from 1 to about 250 or a C1-C60 linear or branched alkyl or cycloalkyl and X=1; R1 and R2 are individually selected from linear or branched alkyl or cycloalkyl groups having 1 to about 60 carbon atoms or are alkyleneoxy and/or aryleneoxy derivatives ranging from 2 to about 250 repeating units of a homo, random, or block co-polymer or are cycloalkyl groups including the ring N to yield ring fused tetrahydroquinolines and julolidine derivatives; R3, R4, R5, R6, R7, R8, R9 and R10 are individually selected from substituents selected from the group of hydrogen, alkyl groups having from 1 to about 18 carbon atoms, alkoxy groups having from 1 to about 18 carbon atoms, acetamido groups, trifluoromethyl groups, sulfonic acid groups, carboxylic acid groups, nitro groups, halogens, and carboxylic acid ester and amide derivatives.
The more preferred polyoxyalkylene and/or polyoxyarylene moieties in Ax include homo, random, and block polymers arising from butylene oxide, propylene oxide, ethylene oxide, styrene oxide and mixtures thereof. More preferably, X is from about 10 to about 100 and R1 and R2 are either methyl or ethyl and more preferably, R3 to R10 are all hydrogen.
The chromophore shown below has the aromatic rings A and B to indicate the regiochemistry of polymeric or waxy chains attached through the heteroatoms (O,N) on rings A and B respectively: 
As described above, oligomeric or polymeric linkages can be effected at each site, such as oxyalkylene groups and/or oxyarylene groups, an aryl, alkyl, or aryl/alkyl (waxy) linkage; as well as resin and aryl, alkyl, or aryl/alkyl (waxy) linkages or resin and polymeric linkages. Representative oligo or polyoxyalkylene and/or polyoxyarylene groups include those derived from at least one butylene oxide, or ethylene oxide, or propylene oxide, or styrene oxide and combinations thereof. The possible resin linkages are those described hereinafter with respect to the isocyanate-derived colored resins in U.S. Pat. No. 5,780,528 issued Jul. 14, 1998 and assigned to the assignee of the present invention.
One of the most preferred compounds of the present invention is illustrated by the following formula (II): 
If the starting materials are a propoxylated acetophenone, bromine, ethylcyanoacetate and diethyaminobenzaldehyde, the preferred four-step synthesis of a particularly preferred species of the present colorant of the present invention is illustrated by the following reaction equations (A); (B); (C); and (D): 
Any conventional reaction conditions normally used for similar halogenation and condensation reactions may be used in the synthesis of these compounds. For example, it may be desirable to substitute either HBr, Cl2 or HCl instead of Br2 as the halogenating agent in reaction equation (A).
The alkyleneoxide and/or aryleneoxide chain of these compounds of the present invention provides the polymeric functionality of these compounds and the reactive hydrogen at the end of this chain may be reactive with reagents such as anhydrides or isocyanates to make anhydride or isocyanate-derived resins or waxes.
The colorant compounds of the present invention may be combined with other conventional phase change ink colorants in making a phase change ink composition. For example, it may be desirable for certain applications to combine the present colorant or colorants with one or more polymeric dyes as described in U.S. Pat. No. 5,621,022 or conventional phase change ink colorants described in U.S. Pat. Nos. 4,889,560 and 5,372,852.
Furthermore, one or more polymeric furanone magenta colorants of the present invention (either with or without other colorants present) may be combined with conventional phase change carrier components including tetra-amide compounds, hydroxyl-functional tetra-amide compounds, mono-amides, hydroxyl-functional mono-amides, tackfiers, plasticizers, antioxidants, and viscosity reducing agents such as those disclosed in U.S. Pat. Nos. 4,889,560; 4,889,761; 5,372,852; 5,621,022; 5,700,851; 5,750,604; 5,780,528; 5,782,966; 5,783,658; 5,827,918 and 5,830,942. Suitable hardening agents may also be employed.
The preferred amounts of each colorant and carrier ingredient will depend upon the particular end-use application.
The polymeric furanone magenta colorants of the present invention may be reacted with isocyanates to make isocyanate-derived colored resins and isocyanate-derived colored waxes similar to those described in U.S. Pat. Nos. 5,750,604; 5,780,528; 5,782,966 and 5,783,658. In making these colored resins and colored waxes, the polymeric furanone magenta colorant is reacted with an isocyanate species in the same manner that the various alcohol or amine species were described as reacting with isocyanate species in these patents. Specifically, the nucleophile comprising a polymeric furanone magenta colorant can also include amines and alcohols, as disclosed in the above referenced U.S. Patents.
It is to be noted that the length of the polymer chain on the magenta chromophore can be lengthened or shortened and can consist of polymers or copolymers and oligomers selected from alkyleneoxide and/or aryleneoxides and/or those polymers consisting of branched portions prepared by the inclusion of glycidyl units. The use of glycidyl units to introduce branching on the polymeric chain enhances the number of reactive sites on the polymeric chain. This approach can be used to tailor the physical properties of the colorant and its derivatives. Typically, the useful number of repeating units on the polymer portion of the chromophore is between about 2 and about 250, more preferably between about 2 and about 100, and most preferably between about 2 and about 30.
It should also be noted that this class of magenta dyes could also be reacted with anhydrides in the type of reactions disclosed in U.S. patent application No. 09/105,308 entitled xe2x80x9cPhase Change Ink Carrier Compositions Containing Anhydride/Alcohol-Based Adductsxe2x80x9d filed Jun. 25, 1998, and assigned to the assignee of the present invention.